The United States and our allies have a waning opportunity to preserve peace through strength. But we must be willing to do something that was just some years ago unthinkable: combat the true engine of our enemies’ power, the Chinese economy. Chinese Communist Party Secretary General Xi Jinping has undertaken "the largest military buildup since World War II," in the words of former Indo-Pacific Command head Adm. John Aquilino. Xi has also fortified the Chinese economy against international sanctions and told his generals to prepare for war. Simultaneous with a robust policy of military deterrence, America and our allies must...